[Bioptic diagnosis of Crohn's disease and ulcerative colitis (author's transl)].

A diagnostic flow diagramm is presented which allows to differentiate Crohn's disease from ulcerative colitis. Colorectal biopsies do allow to make the diagnosis of Crohn's disease even if granulomas are absent. Intact goblet cells in the presence of neutrophil infiltration of the mucosa as well as discontinuous and disproportionate inflammatory changes are the most useful diagnostic criteria in the histology of Crohn's disease. Assessment of these histological abnormalities in carefully orientated and sectioned biopsy specimens is possible in most cases. This diagnostic scheme has been tested by four pathologists independently.